A key element of comprehensive tobacco control programs is accurate population level surveillance which is critical to the planning and evaluation of tobacco control efforts. State tobacco control programs rely heavily on random-digit-dial (RDD) telephone surveys, which only include households with landlines, to estimate smoking prevalence. However, with the growing use of wireless technologies, the RDD survey has become increasingly difficult to implement with confidence, raising concerns of how well surveys of smoking prevalence represent the population of interest. The percent of adults who lived in cell phone or wireless only households increased by more than 150% between early 2003 (3.2%) and late 2005 (8.4%). Specific subpopulations, including young adults, males, and minorities, are more likely to live in a cell phone only household. The cell-phone only population also differs with respect to health behaviors, including cigarette smoking. In due course, the effect of cell phone only households could mask or exaggerate real variations in smoking prevalence. As such, it is critical that we consider innovative methodological approaches to data collection of public health surveillance measures. This R21 grant application is in response to NIH PA-06-343, Methodology and Measurement in the Behavioral and Social Sciences and describes a plan to address gaps in knowledge about the impact of cell-phone only households on RDD surveys, specifically with respect to tobacco use estimates. Accordingly, we will 1) explore the feasibility of cell phone surveying by conducting a cell phone RDD survey in three states in the South, which has the highest cell phone only household rate in the US, 2) compare cell phone only users in our survey with state BRFSS data for specific demographic subgroups and examine health behavior measures, particularly tobacco use, and 3) develop sample weighting methods to combine cell phone only and landline RDD health survey data. Thus, the significance of this proposed research is its potential to generate a better understanding of cell phone only households and how they may impact cigarette smoking prevalence estimates. Furthermore, this knowledge can help direct efforts to improve public health surveillance systems that rely on RDD. Additionally, the implications of this study extend beyond public health surveillance to other research efforts that utilize RDD survey techniques including epidemiological research and public opinion polls. The purpose of this research project is to explore the feasibility of conducting a cell phone only RDD health survey. The relevance of the proposed research to public health is its ability to generate a better understanding of cell phone only households and how they impact public health surveillance in the US. [unreadable] [unreadable] [unreadable]